Core drill



Aug. 9, 1932. M. SCHUERMAN CORE DRILL Filed May 21. 1951 3 SheeS-Sheeb 2 Ibn/ENTER MECHUERMQN HTTDRNETS- Aug 99 1932, M. SCHUERMAN CORE DRILL *5 sheets-sheet s Filed May 2l. 1931 INvx-:NT DR M E EHUEEMQN fw www QTTURNEYS- Patented Aug. 9, 1932 YIABT'IN 8mm, 0F' IAYWOD, CALIFORNIA conn DRILL application and any ai,1'ss1. sei-m ua. ssaooe.

This invention relates to core drills, and.

has for an object vthe provision of a core drill in which various im roved details of construction have been lncorporated as refine- 5 ments, each of which cooperates with the remainder of the drill, causing the entire drill to operate with a greater de ree of surety and efliclency, and thereby making it possible to take cores in formations which are so strati- 1o fied and/or frangible that it has been impossible to take cores successfully with previously available e uipment..

In greater detail, one of the objects of the invention is to provide novel means for 16 mounting the inner barrel Withinthe outer barrel for free rotation with respect thereto, but held with the lower end of the inner barrel in accurate coaxial relationship with respect to the bore of the outer barrel.

20 Another object is to provide several different t pes of improved 'core catchers which may selectivelymounted in operative position below the inner barrel, the particular type of core catcher to be employed de end- 25 ing upon the nature of the formation ing drilled.

Another object is to, provide' a core drill having a plurality of different types of cutter heads which may be selectively mounted upon the lower end of the core drill body so that the particular type of cutter head best suited to the formation being drilled may quickly and easilybe mounted in operative position.

Another object is to provide an improved type of roller cutter head, wherein inner and outer sets of roller cutters are provided, and wherein the number of rollers in the outer set exceeds the number in the inneroset, thereby compensating for the increased amountof wear to which the outer rollers are subjected as a result of their being required'to travel through longer circumferential paths.

A further object in this connection is to so proportion and arrange the lcutters that they are carried by the rotation of the drill, in circular paths of. different diameter than those in which they tend to travel because of their tapering configuration. This causes them to develop a cutting, scraping or chipping action against the formation, in addition to their normal rolling action.

y Another object is to provide a novel welded construction for mounting the journal pins of `the roller cutters upon the head of the core drill, and for interconnecting certain of the pins to impart greater strength to the drill.

A still further object is -to provide a core drill cutter head which uses both roller cutters and drag teeth cutters, the two diierent kinds of teeth cooperating with each other to cut the formation away in an annular path, and leave ra'smooth core standing in the center of the annular cut. Preferably, thedrag teeth are faced' with diamond substitute or its equivalent, so that they will retain their sharp edges and thereby trim the core accurately to size and keep the bore of the hole true to gauge.

The invention possesses other objects and advantageous features, some of which, with those enumerated, will be set forth in the following description of the inventions particular embodiments which are illustrated in the drawings accompanying and forming a par?l of the specification.

Referring to the drawings:

Fig. l is a View in side elevation of a .core drill constructed in accordance with the prinvciples of the present invention.

Fig. 2 is an enlarged vertical medial sectional view, the plane of section being taken upon the line 2-2 of Fig. l, with the direction of view as indicated. A portion of the figure is broken away to reduce its length.

Fig. 3 is a bottom plan view, the direction of View being indicated by the arrow 3 of Fig. 2.

Fig. LLis a horizontal sectional viewtaken upon the line'fl-l of Fig. 2, with the direction of v iew as indicated.

' Fig. 5 is a horizontal sectional view taken upon the line 5 5 of Fig. 2, with the direction of view as indicated.

Fig. 6 is a horizontal sectional view taken upon the line 6-6 "of Fig. 2, with the direction of view as indicated. v

Fig. 7 is anenlarged detail View in vertical section taken upon the line 7--7 of Fig. 6, with the direction of view as indicated.

Fig. 8 is another enlarged view in vertical section taken upon the line 8-8 of Fig. 2, with the direction of view as indicated.

Fig. 9 is an enlarged top plan View of the lower ortion of the core catcher illustrated upon IPig. 2. l Fig. 10 is an enlarged detail view in vertical section showing a slightly modified form of device for attaching the roller cutters to the face of the cutter head. Y Fig. 11 is a detail transverse sectional view taken upon the line 11-11 of Fig. 10, with the direction of view as indicated by the arrows. i

Fig. 12 is a vertical medial sectional view taken through the lower end ofthe bodyof the core drill, and showing slightly modified 'forms of cutter and core catcher. I

Fig. 13 is a bottom plan View, the direction of view being indicated by the arrow 13 of Fig. 12.

Fig. 14 is an enlarged view similar to Fig.

' 3, but showing aslightly modified `form of tubular portion 26 having a threade roller cutter.

Fig. 15 is a detail view in side elevation, the direction of view being indicated by the arrow 15 of Fig. 14.

Fig. 16 is an enlarged view in vertical sec- .tion of the modified form of core catcher which is illustrated upon Figs. 12 and 13.

The core drill of the present invention comprises an outer barrel 21 rand an inner barrel 22 mounted for free rotation thereinside, but

Aheld against axial movement with respect thereto. One of the details of construction of the device of the present invention which represents an improvement over core drills previously produced, lies in the fact that the inner barrel 22 is connected to the outer barrel 21 adjacent only the lower end. of the inner barrel 22, leaving the upper end 23 of the inner barrel 22 free, as far as any immediate connection to the outer barrel 21 is concerned.

The outer barrel 21 comprises an elon ated pin 27 at its upper end, whereby it may removably be attached to the lower end of a drill stem 28, a suitable tool joint 29 having a socket 31 therein complementary to the pin 27 being provided upon the lower-end of the drill stem 28 for this purpose. Also included as a portion of the outer barrel 21 is a sub 32 rigid with the lower end of the tubular portion 26, and a tubular body 33 removably connected to the lower end of the sub 32 b means of a threaded pin 34 rigid with the su 32 and yreceivable within a complementary, threaded socket 36 provided in the upper end of the body 33. An annular recess l37 is formed in the bore 38 of the body 33 at the bottom of the socket 36, the parts being so pportioned and arranged that when the y 33 is threadedly engaged upon the pin t 34 of the sub 32, the upper end of tli'e recess `37 is defined by the lower end 39 of the pin 34.

The means for revolubly mounting the inner barrel v22 within the outer barrel 2l is in the form of an annulus 41 rigidly secured to the inner barrel 22 adjacent the lower end thereof and seated within the recess 37. f The outside diameter of the annulus 41 is' slightly less than the smallest inside diameter of the recess 37 permitting the annulus 41 to be slid into the recess 37 from that end thereof which is proximal to the socket 36. However, when the body 33 is threaded onto the pin 34, upward and downward axial movevment of the annulus 41 is prevented by the end 39 of the pin 34 and the lower Wall 42 of the recess 37, respectively. However, the annulus 41 fits within the recess 37 sufiicieiitly loosely to permit free rotation of the annulus with respect to Vthe outer barrel 21. Preferably, the annulus 41 is rigidly mounted upon the inner barrel 22 as by welding.

A nut 43 adj acent the annulus 41 is threaded to the lower end of the inner barrel 22, and is adapted to engage the bore 38 of the body 33 so as to permit the inner barrel 22 to rotate, but to hold it in coaxial relationship with respect to the outer barrel 21.

In view of the fact that it is often desirable to take a relatively long core, say fifteen or twenty feet in length, I have provided means for rigidly assembling a plurality of sections 46, 47 to define the elongated inner barrel 22. 'In the modification illustrated but two of these sections are shown. It should be understood, however, that any number of sections may be employed, depending upon the length of inner barrel desired. The joint between the sections includes a reduced cylindrical portion 48 extending from the lower end of the upper section 47 and seated within' a complementaryv enlarged portion 49 of the bore of the lower section 46 (see Figs. 6 and 7). The fit between these two portions is sufliciently tight to hold the two sections 46, 47 vaccurately in coaxial alinement. Alined bosses 51 and 52 are formed on the sections 46 and 47, respectively, having vertical holes 53 therethrough. Through the holes 53 of each pair of alined bosses 51, 52, a rod 54 extends, anda pin 56 through each end of each rod 54 holds the sections 46 and 47 rigidly together.

Inasmuch as the core enters the inner bar rel`22 from the lower end, an opening 57 is formed in the upper end ofthe barrel 22 to permit the escape of air and/or circulation Huid which might be entrapped within the inner barrel. A check valve 58 including a ball 59 enclosed within a cage 61 is associated with the opening 57 so asl to' prevent circulation fluid from entering the inner barrel 22 from its upper end. It should be understood that circulation fluid is supplied to the lower end of the core drill from the bore 62 of the drill stem 28 Aby way ofthe bore 63 through the pin 31 which communicates with the bore flowing to the lower end o 64 of the outer barrel 21. Hence circulation fluid is forced downwards around the outside of the inner ,barrel 22 to the recess 37, but inasmuch as the nut 43 fits relatively tlghtly within the bore 64 below the recess 37, the circulation fluid is substantiall revented from the inner barrel 22 by way of the bore 64 of the outer barrel 21. Instead, it is caused to ow through a plurality of passages 66 leading downwards rom the lower wall 42 of the recess 37 f throu h the wall of the body 33 to a shoulderA 67 at t e lower end thereof. Hence all of the passages 66 lead into an annular groove 68 in the upper end of the cutter head 69, whlch is removably attached to the lower end of the body 33 through theexpedient of the threaded pin 71 extending downwards from .the shoulder 67 of the body 33 and received within a. complementary, threaded socket 72 1n the upper end of the cutter head 69. From the annular groove 68 a plurality of passages the inner barrel 22, as will 7 3 extend downwards through the wall of the cutter head 69 so as to deliver the circulation iluid directly to the cutters 74 which are revolu-bly mounted upon the lower face of the cutter head 69.

The cutter head 69 also is annular, having a bore 76 which registers with the bore 77 of the inner barrel 22, so as to permit the core which is cut out from the formation being drilled by the cutters 74 to pass upwards into readily be understood.

Two sets 81 and 82 of roller cutters 74 are provided. In the modification illustrated upon Figs. 1, 2 and 3, there are three cutters in each set arranged in alternation with each other. All of the cutters 74 taper inwards,

i. e., towards the axis of revolution of the core drill. The cutters 74 of the innermost set 82 arejournaled upon pins or spindles 83 which incline upwards and mwards, as

clearly shown upon Fig. 2, whereas the cutters 74 of the outer set 81 are journaled upon pins or spindles 84 which inclinedownwards and inwards. Accordingly, that rtion of the cutting face of each cutter 7 4 o the inner set 82 which engages the formation is inclined upwards and inwards, whereasv the corresponding portion of the face of each cutter 74 of the outer set 81 is disposed substantially at right angles with the axis of revolution of the core drill. In 'other words, the rollers of the two sets'cut the formation in different planes, thereby making it possible y Y which cutters .taper inwardl .Whereas the respective -spindlesnpon w ich the cutters of the two sets are ]ournaled are inclined as described in connection with the modification illustrated upon Figs. 1, 2 and 3, the number of cutters in the outer set 86 exceeds the number of cutters inthe inner set 85, there preferably being four cutters in the outer set and two in the inner set.` The purpose for this arrangement is to compensate for the :tact that the outermost cutters travel through a. circular ath of greater diameter than that traversed y the inner cutters, with the resultthat the are subject to a greater amount of wear. y increasin the number of the cutters which do the major portion of the work, all of the cutters are caused to wear more evenly, thereby prolonging the period fduring which a single set of cutters may be employed.

The cutters 85 and 86 are so arranged that the outer cutters 86 engage the formation in an annular path, the inner circumference 88 of which is spaced slightly outside the outer circumference 89 of the path traversed by the inner rollers 85.v Hence, a relatively thin annular wall of material will be left standing; between the inner and outer rollers 85 and 86 respectively. This wall is so thin that it will be broken down before it attains any appreciable height. Nevertheless, it will present suicient' ridge to develop the tendency for the inner rollers to be pressed radially inwards, and for the outer rollers to be pressed radially outwards on their respec- V.tary cutters 86 lie, the inner teeth 91 are also provided with vertical cutting edges 94 which extendinwards slightly from the bore 96 of the head 69', and the outerteeth 92 have vertical cutting edges 97 which are set outwards. slightly from the outer circumferential wall 98 of the head 69'; The vertical cutting edges 94 of the inner teeth are at slightly less radial distance from the axis of rotation of theJ drill than the extreme innermost portlons of the inner rollers 85, with the result that they traverse the circular path which is indicated at 99 which accurately defines the outside diameter of the core being formed. Similarly, the vertical cutting edges 97 of the outer drag teeth 92 are disposed at slightly greater radial distance from the axis of rotation of the core vdrill than the extreme outermost portions of the outer rolllfl ` er cutters 86, with the result that they move inaeircularpath 100todene accuratelythe bore of the holebeing drilled, which is thus maintained true to gauge. Y

5 Ialsoprefer thattherollersofbothsets 85 and-86 be so proportionedand upon the face of the head 69' that they are dragged in circular paths on account of the rotary motion of the entire core drill, which 1 paths areof dierent diameter from those which would be traversed b the rollers if they were merely permi to roll freely while upon their sides. That is to say, each o the rollers is of conical con- 15 figuration, and accordingly if it .were per- 'ted to roll freely it wouldtraverse a circular tKath. However, the spindles i posi o upon e rollers are journaled are l in such a manner that the rollers are not n carried in the circular paths which they would traverse if they were permitted to roll freely. Instead, they are carried in circular paths which preferably are of slightly greater diameter, the result being that each roller develops ad cutting chipping, or scraping action against the formation, inrvaddition to the rolling action which is 'developed as the cutter lmoves with thereto.`

'A core *catcher 101 is mounted within the lower end of the bore 38I of thehead 33. This core catcher, the design of which also represents a portion of the prent invention, comprises a tubular shell 102 and an laniiulus 103 of substantially the saine inside diameter and .arranged coaxially with respect to the bore 7 7 of the inner barrel 22. The shell 102 floats freel withinthebore38ofthehead33,and is belli against moving upwards therefrom by ment with thel lower end of the inner barrel 22. Downward motion of the shell '102 is limited by the annulus 103, which is' adapted to rotate freely'withinthe head 33, but which is held against axial movement with respect thereto b means of an annular shoulder 104 (see ig. 8) which is received within a recess 106 between the lower end of the pin 71 and the bottom of the socket 72. The shell 102 is provided with a plurality of 'leaf springs 107, each of which is inchned upwards and inwards at its upper end 108, and each of which is rigidly attached to the boreof the shell 102 byrivets 109 or their equivalent.` The annulus 103 is provided with a plurality of teeth 111 which are pivotally mounted at their lower ends upon pivot pins k112 extending between tongues 113 projecting rigidly upwards from the shoulder 104 of the annulus 103. Each ofV these teeth 111 is provided with relatively shar corrugations 114 upon its inner face, an is materially longer than the tongues 113, with the result that when the teeth 111 extend vertically upwards from their respective pivot pins 112'their upper ends 116 are in position I to be engageda by the lower end 117 of the Vfurther downward motion of the core Aplane to` which the axis of the core is per- 121 preferabl corresponds to or is shell 102. The lower end 117 of the shell is inclined downwards and outwards, the up ends of the teeth 111, with the result when the shell 102 moves downwards upon tho upper ends of the 'teeth 111 7 the teeth will be w inwards. Accordingly,afterthecore hasbeenoperated l enoughto cause a core to be received wi theinnerbarrel andtheentiredevi um lifted from esteem of um hoi., A'15. the core will tend to move downwards by its own weight the core drill. Howeverl the curved ends 108 of the le'afsp 10; willengage the core and causethe 102 lsodlsto be carriedretpwnvivard thereweigl, there- 9 A 'posinga tive greatw' tupon tlie teeth 11.1', which as escribed hereinabove will thereby be w radially inwards, causingthem also to bite into the core. An

therefore cause the teeth 111 to be swun to horizontal position, as illustrated upon 9, wherein they are disposed substantially in a pendicular, and in which all the teeth 111 cooperate to define a bottom wall which holds the core within the inner barrel 22, permittin elevation of the core drill to the surface wit out danger of losing the core.

v 4Ou Figs. 12 and 16 a modified form of core catcher 121 is illustrated. 'lhis corecatcher 121 comprises a tubular shell 122 of resilient material, such as vulcanized rubber. The shell 122tapers in an upward i. e., the bore 123 is of less diameter adjacent its l. upper end than adjacent its lower end. -Moreover', the wall 124 of the shell 122 also tapers in au u ward direction, i. e., the wall is of less thi em adjacent its upper end than its lower end, the purpose being to increase the ease with whic the upper end of the shell `122 can be stretched. A shoulder is formed at the lower end of the shell 122, and any suitable means for holding the lower end. to a predetermined diameter are provides:i such as an endless wire cable 127 embedd within the shoulder 126. I also prefer to rovde a pluralit of metal pins 128 ded within the w 124 and projecting into the bore 123, each of the pins inclining upwmik l" and inwards so as to enable them to etrate v a core that tends to move downw within the bore of the shell. The diameter of the bore 123 at the lower end of the core catchtr larger than e diameter of the bore o thi cutter head 69, so as to permit a core to enter the core catcher easily. As the core passes upward within the core catcher, the upper end of the shell 122 will be expanded, thereby permitting' the core to pass freely therethro h. However, owin to thev resilience of the material of which t e core catcher 121 is constructed, it will continually be pressed inwards the core so asarealao that 1:"

any downward motion of the core with respect to the core catcher occurs, the pins 128 will penetrate the core. Hence, any such downward motion of the core within the core catcher will cause the flexible wall 124 thereof to be collapsed and crumpled to such an extent that it fills a suiicient portion of the bore through which the core would otherwise ten to move, to prevent the core from dropping out of the core barrel. A

Still another t pe of cutter head 131 is illustrated upon 1g.'12. lThis cutter head is a drag cutter, and is provided with a plurality of rigid cutting teeth 132 arranged at spaced angular ,intervals about the central bore 133 of the head 131. Preferably, the teeth 132 lie in planes extending radially from the axis of the bore 133, and instead of having perfectly straight cutting edges 134, the cutting edges are serrated with relatively deep irregularities 136, so as to avoid causing the teeth 134 to cut the formation in a single plane. The head 131 is provided with a threaded socket 137 similar to the socket 72 of the head 69, the purpose being to make the heads interchangeable upon the -body 33, whereby either a roller cutter or a drag cutter may be employed with the remainder 'of the core drill, the particular head selected depending upon the nature of the formation to be drilled. A suitable recess 138 is provided at the bottom of the socket 137 to receive the shoulder 126 of the core catcher 121 or the shoulder 104 of the core catcher 101, as the case might be. An annular groove 139 is provided in the upper end of the head 131, and a plurality of passages 141 .extend downward through the wall of the head 131 from the groove 139 to the spaces between the teeth 132, so as to conduct circulation 'fluid to that portion of the head which engages the formation., I

The present invention also contemplates providing novel methods for anchoring the spindles or pins whereby the roller cutters 85 and 86 are journaled upon the head 69.

In the modification illustrated upon Figs. 14 and 15, each of the spindles or pins 146 is permanently and rigidlyattached tothe head 69 by metal 147 which is welded both to the head and to the pin. Preferably, this metal 147 is built up by welding to a material thickness, encircling both ends of the pins 146 whereon the inner rollers are journaled. It is by this mme welded metal l147 that the drag teeth 91 and 92 are rigidly fastened to the face of the head 69. Inasmuch as there are four outer rollers 86 and but two inner rollers 85, the pins 146 associated with the outer rollers 86 will be arranged in pairs, and consequently I prefer that suiicient metal 148 be built up between the inner ends of these pins of each pair, thereby imparting still greater rigidity and strength not only to the pins 146, but to the .entire assembly' of the head 69. Preferably, the inner dra teeth 91 are carried by this metal 148 whic is built up between the pairs of pins 146. The teeth 91 and 92 of both sets may either be separate metal welded to the metal 148, or they-may be built up by the welder to the desired configuration. In either event, I prefer that they be provided with the hard facing, such as diamond substitute or its equivalent, so as to increase the length of time during which they can be used wlthout impairing their sharp edges.

Figs. 10 and 11 illustrate a modied construction for interchangeably mounting the roller cutters in operable position. annular recess 151 is formed in the lower face of the cutter head 152, leaving an annular iange 153 extending downwards todene the bore 154 of the head. The roller cutters, which in this modification are indicated at 156, are journaled upon spindles 157 which extend across the lower edge of the recess 151 so as to position the upper edges of the rollers 156 within the recess, with the result that the liange 153 serves to hold the cutters 156 from sliding oli the spindles 157 into the bore 154.'

Each of the spindles 157 is carried by a block 158 which extends upwards from the spindle 157, and which is of dovetail cross sectional configuration, as indicated at 159 upon Fig; 11. The dovetail portion 159 ofeach block 158 is adapted to be received within a oove 161 formed in the` outer surface of a boss 162 which extends outwardsfrom th outer circumferential face of the head 152. The groove 161 also is of dovetail crosssectional,conliguration, but is wider than the block 159, thereby permitting the reception of a. wedge 163 within the groove 161 beside the block. The wedge 163 is wider at its lower end 164 than'at its upper end, whereas the block 159 is narrower at its lower endthan at'its upper end, with the result that when the wedge 163 is pulled upwards with respect to the block 159, these two members will be forced laterally apart and into tight engagement with the sides of the groove 161, thereby rigidly clamping the block 159 in position. A threaded pin 166 on the upper end of the wedge 163 carries a nut 167 which engages the shoulder 168, which represents the upper end of the boss 162 and also the upper end of the block 159, so that when the nut 167is tightened the wedge 163 will be drawn upwards with-respect to both the head 152 and the block 159. In this manner the spindles 157 for the roller cutters 156 may beattached to the head 152 substantially as securely as though they were welded theretoor integral therewith, even though the spindles 157 may easily be removed whenever it is desired to replace the roller cutters 156.

It is to be understood that the details of the invention as herein disclosed, are subject 139 ennemi@ me spirit or mpc of o apfended claims.

claims 1. Ina'coredrill,atubularhead,asetof 5 two oppositely spindles rigid therew1 an 1n u w an mw -th d A p ards d ards toward the axis o rotation of the head, an inwardly tapered roller cutter jouinaled for free rotation on each of said spindles, and

1 teeth d with said head andha cal cutting edg 'at Slightly less distance from said axis than the rtion of said cutter to trim the core being ormed' by said cutters. v l5 2:11! a ,core drill, a tubular head, a set of four Jspindles rigid with said head and inelining upwards and outwards from the axis of rotation of said head, an inwardly tapered roller cutterjournaled for free rotation on 2 each of ,saidspindles, means for fastexlxl w said spindles to saidhead comp metal builtup around bothends o each of said, spindles and filling the space between the inner ends of adjacent splndles to develo a uni construction, and dragteeth with sai head and having vertical cutting at slightly greater radial distance from said axis than. the outermost portions of said cutters to smooth the'borebelng cut by n said cutters.

- 3.' In a core drill, a tubular head, an inner s'et of two oppositely arranged 'spindles rigid therewith 'and inclining upwards and 1nwards toward the axis of rotation of said u head, an outer set of four spindles rigid with said head and inclining upwards and outwards from said axis, and aninwardly tapered roller cutter journaledior free rotation Y' on eachof said spindles, theouter rollers being fried-.in a circular path of he greater inside diameter than the outsi edi,- ameter of the annular path traversed by the A inner .rollers to leave an annular ridge 'oi formation therebetween.'

'4.' In a core drill, the combination of a tubular head, inner and outer sets of rotary cutters journaled on the lower face offsaid v head, and inner and outer setsgofdrag teeth Y vextending r' 'dly downwards from said head,

f the teetho the inner set being 'toned j ,radially inwards from rollers of sai outer set and the teeth -o the outer set bein positioned radially outwards from the ro ers of'said inner set, said teeth having horizontal cutting u edges substantially in the plane of the .lower-l most rtions of said roller cutters, the teeth of sai inner set havin vertical cutting edges set inwards vfrom the re of said head and -the teeth of said outer set having vertical cutting edges set outwards from the outer circumferential wall of said head.`

In testimony whereof I have signed inyr name to this specification. MARTIN SCHUEBMN. 

